In molding any type of injected piece, it is necessary to extract the piece from the punch of the mold, for which cylindrical ejectors are used, which when properly installed in ejector plates and actuated by the injection machine allow the piece of the mold to be demolded.
In molds which, due to the structure of the injected piece, have areas that do not allow for direct demolding, due to the fact that part of the geometry of the piece has negative zones, it is necessary to install devices known as inclined sliders.
These devices installed on the punch of the mold are always activated by ejector plates at the moment of ejection, by means of inclined bars that slide through the punch of the mold and move by means of sliding mechanisms, fixed to the ejector plates.
In order for the ejection system with the inclined bars to be possible, we have to couple a sliding mechanism that converts the perpendicular movement to the opening of the mold in an angular movement in order to allow these bars to move with the angles in which they have been machined in the mold.
Basically, these mechanisms consist of a sliding body, which slides through friction structures that are fastened to the ejector plates and which, by means of properly machined housings, house the inclined bars with the angles which, being correctly calculated, correspond to each negative to be demolded. The inclined bars move within the punch of the mold during the ejection cycle, and according to the machined angle, the demolding required is obtained, in other words, for each depth of the negative, the angle to be machined must be adjusted.
When the piece to be injected has different areas with negatives of different dimensions, the process gets more complicated, automatically making the development of the project and the machining of the mold more expensive, and furthermore, in many cases the complexity of the design can become further complicated by the different angles required, as well as by the spaces available for installing these devices, since when dealing with inclined holes, the dimensional projection of the same requires much greater surfaces.
When these elements must be installed in small molds, for example in negatives with a maximum of 3 mm., where the dimensions are much smaller, there are a greater number of problems, due to a lack of vital spaces which are necessary for the installation of the system.
In utility model ES1031883U of the same holder as the present application, a molder-ejector accessory for injection molds is described, intended to act as a molding complement for small negatives. This utility model describes a rod fixed to the ejection plate of the mold and provided with a head or figure insert, the form of which coincides with the piece to be obtained. Said head is joined to the rod by means of an elastically deformable neck that allows for the lateral movement of the head with respect to the rod.
The solution we propose is to standardize a very similar system, with regard to the installation in the mold, since it requires minimum space, but which will perform the movements of the demolding by means of sliding that will be carried out through the angular holes machined in the punch of the mold, instead of using the force of the spring, as in the case of the aforementioned utility model, completely doing without the previously mentioned sliders, hence, these spaces, the costly sliders, and the painstaking machining processes for the installation thereof in the molds are no longer required.